<!DOCTYPE html>
<html lang="zh_CN">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        #id1{
            width: 200px;
            height: 199px;
            background-color: aquamarine;
            border-top: 1px solid aquamarine;
        }
        .class1{
            width: 100px;
            height: 99px;
            background-color:brown;
            margin-top: 100px;
        }
    </style>
</head>
<body>
    <div id="id1">
        <div class="class1">
        </div>
    </div>
</body>
</html>